LEAF HOPPERS INJURIOUS TO CEREAL AND FORAGE CROPS 19 



larva state this species is said to depredate on the roots of wheat. 

 Several specimens were sent me by Professor Green, in the year 1822, 

 who received them from a farmer of Virginia." This would place 

 the recognition of the species as an injurious pest as far back as 

 1822, over a century ago. Fitch (6) merely mentions it in his list 

 published in 1851, but does not seem to have recognized its economic 

 importance, and the next mention of it from an economic standpoint 

 appears to have been not until 1890, when the writer (14-) called at- 

 tention to its abundance and its destructiveness in Iowa in connection 

 with other insects, and later described the general appearance of the 

 nymphs and published some details of the life history (17). and 

 described the treatment for it, especially with the hopper dozer (16) . 

 Webster (29) in 1896 gave some information on the life history of 

 the insect. 



Figure 4. — Map showing distribution of Deltoceplialus inimicus 



DISTKIBUTION 



The species is one of very wide distribution in the United States 

 (fig. 4) and appears to be confined to this continent. Van Duzee, 

 in his earlier catalogue (27), credited it to Canada and the United 

 States west to the Rocky Mountains, but later records indicate its 

 general occurrence all the way from Maine to Washington State 

 and south at least to Tennessee and southwest to Kansas. 



In 1909 the writer found it at practically all points where collec- 

 tions were made in the northern part of the country west to Wash- 

 ington, especially in all places where bluegrass occurred. 



Its particular habitat is where bluegrass is the common pasture 

 grass, and this is, perhaps, its favorite food plant. So generally 

 distributed is it that it is almost impossible to sweep over any patch 

 of bluegrass anywhere from Maine to Washington without finding 

 representatives of this species among the leaf hoppers that are cap- 

 tured. Throughout most of this territory it is usually the most 

 abundant of the species taken, and in many cases it far exceeds all 



